I am working on a shared memory plugin for rF2. I am not familiar with quaternions, but from what I read they might save me some cos/sin calls. In fact it's been many years since I worked on 3D games, so pardon for being noob.

Currently, interpolation is done this way:
· Calculate new localRotation based on rotationAcceleration.
· Convert localRotation to world coordinates.
· Build new orientation matrix by rotating around three axes. (this requires 12 sin/cos + 3 sqrt) calls per car.

From what I read here http://www.cprogramming.com/tutorial/3d/quaternions.html I can reduce this to 4 calls + 1 sqrt per car. My issue is I don’t get how to get Angle mentioned in the article from rF2’s localRot? One thing I could think of is to rotate by each component, but that eliminates the benefits and I save nothing.